html,
body {
    margin: 0;
    background: radial-gradient(circle at top left, #228b22, #ba55d3);
    height: 100%;
    overflow: hidden;
    font-family: 'Comic Sans MS', Arial, sans-serif;
}

.app {
    display: flex;
    flex-direction: column;
    align-items: center;
    box-sizing: border-box;
    margin: 0 auto;
    padding: 15px;
    max-width: 700px;
    height: 100%;
}

.quiz {
    flex: 0 0 auto;
    box-sizing: border-box;
    margin: 0 auto 15px auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    border: 3px solid #ba55d3;
    border-radius: 15px;
    background: rgba(255, 255, 255, 0.95);
    padding: 15px;
    width: 100%;
    max-width: 656px;
}

.question {
    color: #2e8b57;
    font-weight: bold;
    font-size: 1.8rem;
    text-align: center;
    text-shadow: 1px 1px 3px #fff;
}

.options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0;
}

.options button {
    position: relative;
    opacity: 1;
    transition: all 0.3s ease;
    cursor: pointer;
    margin: 7.5px;
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.15);
    border: none;
    border-radius: 12px;
    background: linear-gradient(135deg, #2e8b57, #ba55d3);
    padding: 18px 20px;
    overflow: hidden;
    color: #fff;
    font-weight: bold;
    font-size: 1.3rem;
}

.options button.transparent {
    opacity: 0;
    margin-top: 0;
    margin-bottom: 0;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    font-size: 0;
    line-height: 0;
}

.options button::after {
    position: absolute;
    top: -50%;
    left: -50%;
    opacity: 0;
    transition: opacity 0.3s;
    width: 200%;
    height: 200%;
    pointer-events: none;
    content: '';
}

.options button:hover::after {
    opacity: 1;
}

.options button:hover {
    transform: translateY(-3px) scale(1.05);
}

.model {
    display: block;
    flex: 1 1 auto;
    box-sizing: border-box;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    border: 3px solid #2e8b57;
    border-radius: 15px;
    background: linear-gradient(to bottom, #eaffea, #f5e6ff);
    width: 100%;
    max-width: 656px;
}

@media (max-width: 480px) {
    .options {
        grid-template-columns: 1fr;
    }

    .question {
        font-size: 1.3rem;
    }

    .options button {
        font-size: 1.1rem;
    }
}

.options button.correct {
    transform: scale(1.05);
    box-shadow: 0 0 15px rgba(76, 175, 80, 0.7);
    background: linear-gradient(135deg, #4CAF50, #2E7D32);
    color: #fff;
}

.options button.wrong {
    transform: scale(0.95); 
    box-shadow: 0 0 15px rgba(229, 57, 53, 0.7);
    background: linear-gradient(135deg, #E53935, #B71C1C);
    color: #fff;
}

.hint-popup {
    display: flex;
    position: fixed;
    justify-content: center;
    align-items: center;
    opacity: 0;
    z-index: 1000;
    transition: opacity 0.3s ease;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    padding: 15px;
}

.hint-popup.visible {
    opacity: 1;
}

.hint-content {
    position: relative;
    animation: popup-scale 0.3s ease;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    border: 3px solid #ba55d3;
    border-radius: 1rem;
    background: #fff;
    padding: 20px;
    width: 90%;
    max-width: 400px;
    color: #2e8b57;
    font-weight: bold;
    font-size: 1.1rem;
    text-align: center;
    text-align: center;
}

@keyframes popup-scale {
    from { transform: scale(0.9); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.hint-image {
    margin-top: 10px;
    border-radius: 0.5rem;
    width: 100%;
    height: auto;
}

.hint-close {
    position: absolute;
    top: 8px;
    right: 10px;
    cursor: pointer;
    border: none;
    background: none;
    font-size: 1.5rem;
}